Flat-panel and projection displays are being developed which utilize liquid crystals materials to produce high quality images. These displays are expected to supplant cathode ray tube (CRT) technology and provide a more highly defined television picture. A promising route to large scale high quality liquid crystal displays (LCDs), for example, is the active-matrix approach in which thin-film transistors (TFTs) are co-located with LCD pixels.
Projection displays employing LCDs generally include five different components: a white light source, a condensing optical system mounted an optical system configured to enlarge the image from the LCD onto a viewing surface and in certain systems the viewing surface as well.
Each LCD includes a layered structure having polarizing filters and a circuit panel. A volume between the circuit panel and one filter plate is filled with a liquid crystal material. This material will rotate the polarization of light when an electric field is applied across it between the circuit panel and a ground affixed to the filter plate. Thus, when a particular pixel of the display is turned on, the liquid crystal material rotates polarized light being transmitted through the material so that it will pass through a second polarizing filter. Alternatively, application of the field can also be used to further limit the amount of light transmitted through the LCD to define an image.
A need exists, however, for improved LCD systems having the desired resolution and speed, and providing for ease of use and reduced cost of fabrication.